始于质体/叶绿体的ABA信号通路  

An Abscisic Acid Signaling Pathway Starting from Plastid/Chloroplast

作　　者：张大鹏[1] 

机构地区：[1]清华大学生命科学学院,北京100083

出　　处：《植物学报》2011年第4期361-369,共9页Chinese Bulletin of Botany

基　　金：国家自然科学基金(No.90817104);国家基础研究重大专项(No.2003CB114302);国家重大科技专项(No.2008ZX08009-003)

摘　　要：该文全面评述了植物激素脱落酸(ABA)受体的研究进展概况,重点介绍细胞内ABA受体ABAR/镁螯合酶H亚基CHLH对ABA信号感知和向下游转导的研究进展,总结了ABAR介导的、起始于质体/叶绿体的ABA信号通路。ABAR是一个跨越叶绿体被膜的蛋白质,其N-端和C-端暴露在细胞质中;ABAR在细胞质一侧的C-端部分与一组WRKY转录因子(WRKY18、WRKY40、WRKY60)相互作用。WRKY18、WRKY40和WRKY60是一组转录抑制因子。它们互相协作,抑制下游重要的ABA信号调节子基因(如ABI4、ABI5、ABF4和MYB2等)的表达,从而负调节ABA信号通路。WRKY40是其中的核心调节子,WRKY18协助加强WRKY40对ABA信号的负调节。ABAR与ABA信号分子结合后,可以刺激WRKY40从细胞核转移至细胞质,促进ABAR与WRKY40的相互作用;进而激发一种未知因子(或信号系统),阻遏WRKY40的表达,从而解除WRKY40对ABA响应基因转录的抑制,最终实现ABA的生理效应。这些发现描述了一个从信号原初识别到下游基因表达的新的ABA信号通路。论文最后对未来该领域的研究方向进行了讨论。We give a brief review of the advances in studies of ABAR/CHLH-mediated abscisic acid（ABA） sensing and downstream signaling from early events starting from plastids/chloroplasts to downstream gene expression.ABAR spans the chloroplast envelope,and the cytosolic C terminus of ABAR interacts with a group of WRKY transcription factors,WRKY40,WRKY18,and WRKY60,which function as negative regulators of ABA signaling in seed germination and post-germination growth.WRKY40,a central negative regulator,inhibits the expression of ABA-responsive genes such as ABF4,ABI4,ABI5,and MYB2.In response to an ABA signal that recruits WRKY40 from the nucleus to the cytosol and promotes ABAR-WRKY40 interaction,ABAR relieves ABA-responsive genes of inhibition by repressing WRKY40 ex-pression.These findings uncover a novel ABA signaling pathway from the early signaling events to downstream gene expression.We also discuss future studies needed to understand the complex ABAR-mediated ABA signaling pathway（s）.

关 键 词：脱落酸(ABA) 脱落酸受体 信号转导 

分 类 号：Q945[生物学—植物学]